The Response of Durum Wheat to the Preceding Crop in a Mediterranean Environment

Table 2

Effects of the preceding crop on preplant residual soil nitrate N (0–40 cm depth).

Preceding crop	Residual soil nitrate N (mg kg^−1)
	2007	2008
Alfalfa	12.3^a	10.6^a
Maize	7.9^b	7.1^b
Sunflower	6.5^b	5.7^b
Wheat	4.2^c	3.3^c

Within columns, numbers followed by the same letter are not significantly different at ≤ 0.05.